Test switches are known for use in combination with watt hour meters. When the watt hour meter is used for a commercial facility the test switches may include a plurality of knife blade switches which allow a known load to be measured which allows the accuracy of the watt hour meter to be determined. If the watt hour meter accuracy is not within the required parameters the watt hour meter is replaced. An example of a prior art test switch is shown in FIG. 5. The test switch of FIG. 5 includes a plurality of knife blade switches (generally referenced as 27) which facilitate connection to the known load in order to measure the accuracy of the meter. As shown nonconductive barriers 31 may be used to segregate knife blade switches.
The design of such test switches must meet the safety standards of a variety of safety standards, such as ANSI or NEPA. Occasionally when a new code is adopted wholesale changes in electrical equipment must be made.